     (key elt)))
 
 (defn dval
+  {:doc "Returns the value part of a KV or MapEntry."
+   :added "0.1.0"}
   [elt]
   (if (instance? KV elt)
     (let [^KV kv elt]

        (f elem num)))))

(defn dpartition-by
  ([f num options ^PCollection pcoll]
   (let [opts (assoc options :label :partition-by)
         ptrans (Partition/of num (partition-fn f))]

  [^DoFn$ProcessContext c]
  (.output c (.element c)))

(defn make-nippy-coder
  {:doc "Returns an instance of a CustomCoder using nippy for serialization"
   :added "0.1.0"}
